Crystalloid cardioplegia versus cold blood cardioplegia in aortic arch surgery: A noninferiority randomized trial

The optimal cardioplegic solution to use during aortic surgery remains unclear. While cold blood cardioplegia (BCP) has metabolic advantages, crystalloid cardioplegia (CCP) offers practical benefits. This trial investigated whether cold CCP is noninferior to cold BCP in preserving postoperative left ventricular ejection fraction (LVEF).

In this single-center, patient- and assessor-blinded, parallel-group noninferiority randomized trial, 52 adult patients undergoing elective aortic arch replacement were randomized 1:1 to receive cold BCP or CCP. The primary endpoint was LVEF on postoperative day 7. The noninferiority margin was set at -7%. Secondary endpoints included change in LVEF, mortality, low-output syndrome, myocardial infarction (MI), creatine kinase MB isotype (CK-MB) release, left ventricular diastolic dysfunction, right ventricular systolic dysfunction, stroke, atrial fibrillation, pacemaker implantation, mediastinal drainage, reexploration for bleeding, and acute kidney injury.

The median aortic cross-clamp time was 96 minutes. Baseline LVEF was similar in the 2 groups (BCP, 61.1 ± 5%; CCP, 61.7 ± 5%; P = .66). The mean difference in postoperative LVEF (CCP - BCP) was 1.23%, with a 95% confidence interval of -5.48% to 2.69%, exceeding the noninferiority margin and confirming noninferiority (P = .0041). Peak CK-MB levels were comparable in the 2 groups (BCP, 35.0 ± 15 U/L; CCP, 41.6 ± 22 U/L; P = .22), although levels at 7 hours and 24 hours were lower in the BCP group (P = .034 and .046, respectively). One in-hospital death occurred in the BCP group, and 1 case of low output syndrome occurred in the CCP group. Postoperative MI occurred in 4 patients (2 per group), with no significant differences in other secondary endpoints.

Cold CCP appeared to be noninferior to cold BCP for myocardial protection in elective aortic arch replacement, as suggested by comparable postoperative LVEF.